Linker error on Arch

[pkookrthy]

I get a Linker error on Arch:

libHScryptonite-0.29-717e3026048e355515ccc1fd8abeed450db0ef8d63bbf8bb8b1a7d87bbff5b11.a(ed25519.o): multiple definition of 'batch_point_buffer'

libHSed25519-donna-0.1.1-1239fe7092277c5cdd70eb45b6e85454704fc0d908ec7072245a1d50122627d5.a(ed25519.o): previous definition here

collect2: error: ld returned 1 exit status
`gcc' failed in phase `Linker'. (Exit code: 1)

ghc-8.6.5
cabal-3.6.2.0

[emilypi]

This is not pact problem (it's a problem with your Haskell setup on Arch), but I'm willing to keep this issue open and hash this out so it doesn't come up again as an issue.

Have you tried deleting your ~/.cabal/store and retrying from scratch? Multiple object file definitions are often the result of corrupt build caches for Cabal in your home directory.

[pkookrthy]

deleted ~/.cabal and installed fresh ghc with ghcup, the problem still persists.
is there a different build system than cabal v2-build?
If I remember correctly a few month ago there were stack .yaml files and it built fine

[emilypi]

Can you paste the rest of the log output? If this is a linker error, then it may be a problem with not being able to link libgmp-dev, which is required for GHC usage.

[pkookrthy]

thanks for the "quick google search" but gmp is already installed, even if I am missing a library it must be a cryptography related one no? the error clearly is coming from some kind of conflict between cryptonite and ed25519-donna.

what is the purpose of these sussy flags in the cabal file?

flag cryptonite-ed25519
  description: use cryptonite instead of ed25519-donna
  default:     False
  manual:      True

and also

    if flag(cryptonite-ed25519)
      cpp-options: -DCRYPTONITE_ED25519
    else
      build-depends:
        , crypto-api
        , ed25519-donna

seems to me someone was solving a similar problem in a hacky way.

[pkookrthy]

this solved the probem:

first

cabal v2-configure -f cryptonite-ed25519

and then

cabal v2-build